Steam cylinder oil



Patented Dec. 15, 1942 STEAM CYLINDER on.

Knapel F. Schiermeier, Alton, Ill., assignor to Shell DevelopmentCompany, San Francisco, Calilfl, a corporation of Delaware No Drawing.Application October 27, 1941,

' Serial No. 416,755

10 Claims. (Cl. ass-4s) This invention relates to lubricating oils, andmore particularly to compounded lubricants which are effective in thepresence of steam, i. e. are suitable for use in the lubrication ofsteam engines and the like.

Lubricants to be used in steam engines must possess certain propertiesnot required of most lubricants. In such engines the temperatures may beof the order of 550 F. and higher if superheated steam is employed, andaccordingly the lubricant must have high heat-resisting qualities toprevent gumming and carbon formation. The presence of moisture in asteam engine is inherent in its operation, even though such engines maybe operated with superheated or dry steam; at certain stages in theoperation moisture or wet steam will usually be present. Moisture tendsto scour the metal parts free of oil and prevent the spread of oil overthe surface to be lubricated. As a-result the relative movements ofvarious metal parts may become jerky due to increased friction.

The lubrication of the moving parts of such engines is usuallyaccomplished by atomizing the lubricant through a quill into the steamline and utilizing the steam to carry the lubricant to the moving parts.Inasmuch as superheated steam added a dispersing agent and petroleumresins, the various components being selected as will be described inthe following.

Oils for use as base stocks in the compounding conditions, and theyshould be free from asis not a good carrying medium for lubricating oil,the latter must be readily atomizable to be effective in the presence ofdry steam. Further, I

such oils must be thermally stable to prevent carbon deposits fromforming and clogging the quill.

It is an object of this invention to provide a lubricant having greaterutility in the presence of steam than had lubricants heretofore providedfor such a purpose. It is another object of this invention to provide alubricant for use in the presence of dry or wet steam. Another object ofthis invention is to provide an oil that will read ly spread to providean oil film on a surface to be lubricated in the presence of steam.Still another object is to provide an oil of greater adherence to metalsurfaces in the presence of steam than oils heretofore employed. Afurther object is to provide an oil that is thermally stable in thepresence of superheated steam.

I have found that one or more of the foregoing objects can be achievedwith the aid of my new steam cylinder oil which comprises a heavy,asphalt-free lubricating oil to which have been phaltenes which readilycarbonize and thereby interfere with proper lubrication. Pennsylvaniasteam-reduced or, preferably,.clay-filtered stocks or Midcontinent orCalifornia deasphalted or, if desired, solvent-extracted bright stocks,are suitable. In general, reflned oils are preferred for reasons ofpreventing formation of coke-like material on heated metal parts to .belubricated. On the other hand, over-treated oils which readily oxidize,thereby forming excessive amounts of acidic oxidation products andsludge, should be avoided because they may cause severe corrosion fural;nitrobenzene, .phenol, cresols, dichlordi ethylether, antimonytrichloride, etc.; or of a pair of mutually immiscible solvents, onebeing selective for aromatics and the other for parafiins,

such as phenol and propane, etc.

Other refining methods may comprise treating with sulfuric acid, clay,aluminum chloride, etc.

Petroleum resins as herein defined are highboiling organic compoundsnormally contained in unextracted bright stocks, which compounds arecompletely soluble in 86 B. naphtha, possess molecular weights in excessof about 500, have specific dispersions above 200, and containsubstantial proportions frequently of the order of 3 Or more ofcomponents adsorbable on silica gel or other acidic adsorbents and therecovery of the adsorbed compounds, etc. Methods for producing suchresins are described in Merrill.

, contain appreciable amounts of resins naturally associated therewith,and such oils obviously require smaller quantities of additional resinsthan stocks which are substantially devoid of them. However, as a rule,the natural content of resins is insufficient for best results, and oilswhich naturally contain resins invariably are benefited by the furtheraddition of resins, although perhaps not to so large an extent as oilsoriginally free of resins.

As a rule, useful amounts of resins to be added range from about 1%-l5%by weight of the base stock, and more often from 2%-10% To the mixtureof base stock and petroleum resins, a minor proportion of the order of05% to 1%, and preferably from .1% to 5%, of a dispersing or emulsifyagent capable of spreading hydrocarbon oil on metal surfaces wetted bywater is added. Such an additive preferably comprises a salt of analkali metal with an organic detergent-forming acid. However, alkalineearth metals or amino base salts with such acids may be used.

The organic detergent-forming acids may comprise, for example,carboxylic acids of the type RCOOH, such as lauric, palmitio, stearic,oleic, linoleic, ricinoleic acids, oxidized parafiin acids, tall oilacid, rosin acids, abietic acid, wool fat acids, naphthenic acids,alkylated benzoic and naphthoic acids. aromatic fatty acids such asphenyl stearic acid, terpenic acids, etc.; acids of the sulfonic acidtype RSO3H, for example petroleum sulfonic acids such as the mahoganyacids or green acids produced in the manufacture of medicinal oils bytreatment with fuming sulfuric acid of parafiinic mineral oils such aslube oil, etc.; or of various aliphatic or alicyclic sulfonic acids suchas fatty sulfonic acids, fatty aromatic sulfonic acids, naphthenesulfonic acids; or of sulfonic acids of various aromatic hydrocarbons,particularly those which contain one or more alkyl radicals and whichmay contain non-functional substituents, such as various alkylatedbenzenes, diphenyls, xylenes, diphenyl methanes, naphthalenes,anthracenes, phenanthrenes, tetralines; alkyl phenols such as thosecontained in cracked petroleum distillates; alkylatedchlornaphthalene's, naphthylamines, diphenyl oxides, chlorinateddiphenyl oxides, diphenyl sulfides, diphenyl amines, phenylnaphthylamines, dinaphthyl oxides, sulfides, or amines; alkylatedpyridines, quinolines, isoquinolines, pyrral, pyrrolidines, piperidine.thiophenes, thiophanes, etc.; or of various sulfonic acids of carboxylicacid esters or amides: acids of the sulfuric acid ester type, ROSOsH,for example turkey red oil, sulfated fish oils, sulfated fatty acidssuch as mono lauryl, cetyl, stearyl, etc, sulfate acids; or mono estersof sulfuric acid obtained by treating with strong to moderately strongsulfuric acid various olefines or alcohols such as the long-chainoleflnes obtained in the vapor phase cracking of wax at about 550 C- 560C., polymers obtained in the polymerization of normally gaseous olefineswith inorganic polyoxy acids or Friedel-Crafts catalysts, fatty ornaphthenic alcohols obtained in the catalytic reduction of fatty ornaphthenic acids, alcohols obtained by condensation of ketones oraldehydes followed by hydrogenation; or alkyl aromatic mono esters ofsulfuric acid, etc. A convenient source for many of the active sulfateester acids is the sludges obtained in the. acid treatment of crackeddistillates, or the spent acids obtained in the polymerization ofolefines or in the alkylation of isoparaffins with olefines withsulfuric acid. Suitable organic detergent-forming acids such as havebeen described in the foregoing may, if desired, contain non-functionalradicals such as halogen, hydroxyl, ether, amino, imino, hydrosulfide,sulfide, vcarboxyl ester, etc.

Fatty oils such as tallow, frequently used as steam cylinder oils,should be avoided as under superheat conditions they decompose and formdeposits of carbon as well as corrosive acids.

It will be understood that the foregoing order of mixing of the variouscomponents of my compounded oil need not be observed.

In order to evaluate the lubricants prepared in accordance with theinvention, the following experiments were performed.

A piston in a steam engine was lubricated with a fixed quantity of theoil under test, after which it was run as long as possible at a constantsteam pressure Without the addition of further amounts of oil. Thenumber of strokes made and the smoothness of operation were noted andwere taken as indicative of the quality of the oil. Thus, an oil thatwas well dispersed and adhered to the surface to be lubricated in thepreskept well oiled so that practically all load on the pump was dueonly to friction in the steam end. A stroke counter was attached to thepump.

The testing procedure was as follows: The lubricator and its connectionto the pump were carefully cleaned with gasoline and ether. They werethen flushed and filled with the oil to be tested. The pump was thenoperated at a constant speed for 60 minutes, with the lubricating feedset at a definite rate. Lubrication was then stopped, the stroke counterplaced in position, and the operation of the pump continued at theconstant speed. The strokes were counted until the pump would no longeroperate at 2.50 pounds pressure. The type of operation of the pump wascarefully observed throughout the test and judged as smooth, jerky, orvery jerky.

In order to prevent test from being afiected by carryover from aprevious oil which might have remained in the pump, a blank run was madeon unfiltered bright stock between each stock on a different oil.Consecutive tests on different oils would not be run until a correctresult was obtained for the intermediate blank bright stock test.

The following table shows the results of comparative tests as aboveoutlined in the presence of wet steam on the newly compounded oils ofthe invention with conventional steam lubricating oil.

oii s mpl Siwkes gli li r ii 150 at 210 F. Unfiltered bright stock.

. 150 at 210 F. Unfiltered bright stock I plus 8% acidless tallow.

. 150 at 210 F. Unfiltered bright stock 1 plus 5% petroleum resin plus2% sodium oleate.

. 150 at 210 F. Dewaxed steamrefined stock.

. 150 at 210 F. Dewaxed steamrefined stock plus 8% tallow.

6. 150 at 210 F. Dewaxed steamretlned stock plus, 5% petroleum resins.

7. 150 at 210 F. Dewaxed steamrefined stock 1 plus 2% sodium oleate.

8. 150 at 210 F. Dewaxed steamrefined stock plus 5% petroleum resinsplus .2% sodium oleate. 9. l50 at 210 F. -Dewaxed steamrefined stockplus 4%.petroleum resins lus .2% sodium oleate'plus .3 0 sodiumsulfonate of petroleum.

Less than 500.

Very jerky.

Smooth.

Less than 500. Very jerky.

13,400. l Smooth.

1 Midoontinent residual stock, propane-deasphalted and dewaxed. I Duosolextracted stock, propane-deasphalted and dewaxed.

The above results show that the newly compounded oils (Examples 3, 8, 9)gave far better results than conventional unblended oils or oils blendedwith a soap or tallow. The effect of the combination of petroleum resinswith soap in the oils of the invention is more than additive in that, aswill be noted from the table, the combination improved operation farmore than might be expected from the effect of soap or petroleum resinswhen added alone to a lubricating stock.

The oils were subjected to a second test to determine their chemicalvstability under high temperatures of the order of 550 F. attained byemploying superheated or dry steam. They were injected into a highlysuperheated steam line through a quill, simulating actual enginelubrication practiced over a period of time.

It was found that compounded oils containing tallow'decomposed on thequill, tarnished it, and

formed carbonaceous deposits, while the steamoleate-resin blends leftthe quill bright and free of any deposits.

I claim as my invention:

' 1. A steam cylinder lubricating oil consisting essentially of amineral lubricating oil free from asphaltenes and of viscosity suitablefor steam cylinder oil containing a minor proportion of a dispersingagent selected from the group consisting of salts of alkali metals,alkali earth metals and amines with organic detergent forming acids,which agent is capable of spreading hydrocarbon oil on metal surfaceswetted by water, and from about 1% to (about 15% by weight of addedpetroleum resins."

2. The composition of claim 1 in which the lubricating oil is a refinedhydrocarbon oil of a viscosity of the order of 100-300 seconds S. U. at210 F,

3. The composition of claim 1 in which the amount of the dispersingagent is between .05% and 1%.

4. The composition of claim 1 in which the amount of the dispersingagent is between about .l% and about 5%.

5. A steam cylinder lubricating oil consisting essentially of a minerallubricating oil free from asphaltenes and of viscosity suitable forsteam' cylinder oil containing a minor proportion of an alkali metalsalt of an organic detergent-forming acid and from about 1% to about 15%by Weight of added petroleum resins.

6. A steam cylinder lubricating oil consisting essentially of a minerallubricating oil free from asphaltenes and of viscosity suitable forsteam cylinder oil containing a minor proportion of an amino base saltof an organic detergent-forming acid and from about 1% to about 15% byweight of added petroleum resins.

7. A steam cylinder lubricating oil consisting essentially of a minerallubricating oil free from asphaltenes and of viscosity suitable forsteam cylinder oil containing a minor proportion of an alkaline earthmetal salt of an organic detergentforming acid and from about 1% toabout 15% by weight of added petroleum resins.

8. A steam cylinder lubricating oil consisting essentially of a minerallubricating oil free from asphaltenes and of viscosity suitable forsteam cylinder oil containing a minor proportion of sodium oleate andfrom about 1% to about 15% by weight of petroleum resins.

9. A steam cylinder lubricating oil consisting essentially of a minerallubricating oil free, from asphaltenes and of viscositysuitable forsteam cylinder oil containing a minor proportion of an ture isintroduced into a steam cylinder.

KNAPEL F. SCHIERMEIER.

